Antsy Challenge


Antsy Retrieval

The Antsy unit
Side view of the Antsy unit. Three legs either side connected to drive motors (left is on port B, right legs on port C motor). The head houses an InfraRed sensor connected to port 4 and the 'tail' is a colour sensor connected to port 3
Viewing Antsy's underneath. This highlights the presence of a touch sensor as part of the walking mechanism which is connected to port 1

Being a walking robot, Antsy requires a little pre-programming to ensure the legs are calibrated to be in opposite positions.

Here is the leg calibration information (pdf), if you're interested in how it works.

No need to include this in any program you provide, as the robot calibration will be run before each test by us.

Throughout the programming of Antsy you need to remember to always turn both leg motors equal amounts, including when turning. This means when turning right, you need the left motor to move the same amount backwards as the right is moving forwards. Failure to do so could lead to the robot toppling over.

Click on the below heading to reveal the challenge map for Antsy - this is achievable using either software option.

The Challenge: Antsy needs to navigate her way to the exit

A robot trapped in a maze. The challenge is to navigate a maze with left turns, right turns and dead-ends. The catch is that the lighting in the room will change colour due to danger of ceiling collapse. If red light the robot must stop, yellow means move slowly, green means safe to proceed and blue will terminate the program at the end of the maze

Warning! The ceiling is unstable. If red light on, Antsy needs to stop and wait, yellow means move slowly, green means safe to proceed, the exit is lit in blue to terminate program.

Below are the figures to assist in this challenge for the Antsy unit.

Action Left motor power Right motor power Number of rotations Threshold value
To travel forward one grid square*1 100% 100% 5 n/a
90° turn right 50% -50% 3.5 n/a
Wall detection n/a n/a n/a <10

These are not perfect, as the legs do not have much grip on the maze floor surface.
This means you may want to consider a strategy that will counter this issue.

*1 The maze is made on a 5x5 square grid

Would your program need to be altered to reach the finish line on this new map? Why? If so, then how?

The start is identical to the above maze, however an additional corridor featuring more right-angled turns has been added on the exit route

Members of the Aberystwyth Robotics Club can share a link to their MakeCode program or send a Lego Mindstorms program directly through the club's Discord server.

Non-members who wish to see if their program works can email either the Lego Mindstorms file or a link to their MakeCode program